Gas exchange valve control system for internal combustion engines and internal combustion engines
The gas exchange valve control system on a common camshaft with separate drive shafts for intake and exhaust cams addresses the challenge of independent valve timing, enhancing flexibility and space efficiency in large internal combustion engines.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- EVERLLENCE SE
- Filing Date
- 2025-09-22
- Publication Date
- 2026-04-22
AI Technical Summary
Existing gas exchange valve control systems for large internal combustion engines, such as those used in ships, lack the ability to provide independent and flexible adjustment of intake and exhaust valve timing, necessitating separate camshafts for intake and exhaust cams, which complicates retrofitting and increases space requirements.
A gas exchange valve control system where intake and exhaust cams are mounted on a common camshaft, with each cam being driven by separate drive shafts, allowing independent and flexible valve timing through phase adjusters, and optionally using a common gear for cams to reduce gear count.
Enables independent and flexible valve timing with minimal installation space, facilitating easy retrofitting of existing engines and maintaining engine structure integrity.
Smart Images
Figure 2026068693000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a gas exchange valve control system for an internal combustion engine and an internal combustion engine.
Background Art
[0002] Large internal combustion engines are employed in ships, for example, as ship engines. In the case of large internal combustion engines, the cylinders have a piston diameter of at least 140 mm, particularly at least 175 mm.
[0003] An internal combustion engine includes a plurality of cylinders. Each cylinder of the internal combustion engine includes at least one intake valve and at least one exhaust valve, and combustion air can be introduced into each cylinder via at least one intake valve, and exhaust gas can be discharged from each cylinder via at least one exhaust valve. In addition to the gas exchange valves, the cylinders of the internal combustion engine include a fuel metering device for introducing fuel into each cylinder.
[0004] To control the gas exchange valves of the cylinders of an internal combustion engine, the internal combustion engine includes a gas exchange valve control system. Such a gas exchange valve control system includes at least one camshaft.
[0005] In practice, there are known internal combustion engines in which an intake cam for controlling the intake valve of a cylinder and an exhaust cam for controlling the exhaust valve of the cylinder are arranged on separate camshafts, respectively. Further, there is known a gas exchange valve control system for an internal combustion engine in which an intake cam for controlling the intake valve and an exhaust cam for controlling the exhaust valve of a cylinder are arranged on at least one common camshaft. The camshaft supporting both the intake cam and the exhaust cam is called a mixed camshaft.
[0006] Until now, gas exchange valves with camshafts containing both intake cams for controlling intake valves and exhaust cams for controlling exhaust valves have not allowed for independent and flexible adjustment of the valve timing of the intake and exhaust valves in the cylinders of an internal combustion engine. This has required, until now, the intake and exhaust cams to be located on separate camshafts. While it is possible to place the intake and exhaust cams together on at least one camshaft, there is a need for a gas exchange valve control system for internal combustion engines that enables independent and flexible valve timing of the intake and exhaust valves in the cylinders of an internal combustion engine. [Overview of the Initiative] [Problems that the invention aims to solve]
[0007] Starting from this, the present invention is based on the objective of creating a new type of gas exchange valve control system for internal combustion engines and an internal combustion engine having such a gas exchange valve control system. [Means for solving the problem]
[0008] This objective is achieved through the gas exchange valve control system described in claim 1 and the internal combustion engine described in claim 11.
[0009] In the first modification of the present invention, the intake cam, and in the second modification, the exhaust cam, are non-rotatably mounted on their respective camshafts and can be driven from their respective camshafts. In the first modification, the exhaust cam, and in the second modification, the intake cam, are rotatably mounted on their respective camshafts and can be driven by separate drive shafts. In the gas exchange valve control system according to the present invention, in the first modification, the intake cam is non-rotatably mounted exclusively on each camshaft, and in the second modification, the exhaust cam is non-rotatably mounted exclusively on each camshaft, whereas in the first modification, the exhaust cam, and in the second modification, the intake cam, are rotatably mounted on their respective camshafts and can be driven from their respective separate drive shafts. Thus, despite arranging the intake and exhaust cams on a common camshaft, it is possible to provide independent and flexible valve timing for the intake and exhaust valves of the cylinders of an internal combustion engine with minimal installation space requirements. In particular, existing internal combustion engines can be easily retrofitted or converted using the gas exchange valve control system according to the present invention.
[0010] Preferably, each camshaft and each separate drive shaft are meshed in mesh via drive gears, i.e., via a camshaft drive gear located on each camshaft and a drive shaft drive gear located on each drive shaft. This allows each drive shaft to be driven starting from each camshaft.
[0011] Preferably, each camshaft is assigned a phase adjuster to twist its respective camshaft relative to the camshaft drive gear. Alternatively or additionally, each driveshaft is assigned a phase adjuster to twist its respective driveshaft relative to the driveshaft drive gear. Each phase adjuster allows the camshaft drive gear to twist relative to the camshaft and the driveshaft drive gear to twist relative to the driveshaft, thereby providing corresponding flexible valve timing in the intake valve and / or exhaust valve region.
[0012] In the first modification of the present invention, each exhaust cam preferentially meshes with the gears of the respective drive shaft via individual gears, and in the second modification of the present invention, each intake cam preferentially meshes with the gears of the respective drive shaft via individual gears. Alternatively, each of the two exhaust cams in the first modification of the present invention, and each of the two intake valves in the second modification of the present invention, meshes alternately with the gears of the respective drive shaft via a common gear. In particular, when each exhaust cam in the first modification of the present invention, and each intake cam in the second modification of the present invention, meshes with the gears of the drive shaft via individual gears, the rest of the engine structure, especially the shape and arrangement of the pushrods and rocker arms, can remain unchanged compared to an internal combustion engine having a mixed camshaft in which the intake and exhaust cams are each non-rotatably positioned. However, when each of the two exhaust cams in the first modification of the present invention, and each of the two intake cams in the second modification of the present invention, are operably connected to the gears of the drive shaft via a common gear, the shape and arrangement of the pushrods and rocker arms must be adapted.
[0013] Preferably, a fuel cam used to control the fuel pump can be immobilely mounted on each camshaft and driven from each camshaft. The fuel delivered by the fuel pump can be individually introduced to each cylinder via an electronically or electrically controllable fuel metering device. This allows for a particularly compact design of the internal combustion engine. [Brief explanation of the drawing]
[0014] [Figure 1] This is a schematic diagram of an excerpt from the camshaft of a first internal combustion engine according to the present invention. [Figure 2] This is a schematic diagram of an excerpt from the camshaft of a second internal combustion engine according to the present invention. [Figure 3] This is a schematic diagram of an excerpt from the camshaft of a third internal combustion engine according to the present invention. [Figure 4] Figures 1, 2, or 3 are further schematic diagrams of the camshaft. [Figure 5] This is an alternative diagram for Figure 4. [Modes for carrying out the invention]
[0015] Preferred further developments of the present invention can be derived from the lower claims and the following description. Embodiments of the present invention will be described in more detail below with reference to the drawings, but the present invention is not limited thereto.
[0016] Figure 1 shows an excerpt of a first gas exchange valve control system 10 according to the present invention for an internal combustion engine, particularly a large internal combustion engine, where Figure 1 shows a camshaft 11 on which both intake cams 12 for controlling the intake valves and exhaust cams 13 for controlling the exhaust valves of a bank of cylinders arranged adjacent to each other in a row. In Figure 1, the exhaust cams 13 are non-rotatably mounted on the camshaft 11, particularly by press-fitting. In contrast, the intake cams 12 are rotatably mounted on the camshaft 11 in Figure 1. The intake cams 12, rotatably mounted on the camshaft 11, can be driven from a first separate drive shaft 14.
[0017] The drive shaft 14 extends parallel to the camshaft 11, and each intake cam 12, which is rotatably mounted on the camshaft 11, is operationally connected to a gear 15 that meshes with a gear 16 located on a separate drive shaft 14. Thus, the rotational motion of the drive shaft 14 is transmitted to each intake cam 12 via the gears 15 and 16 that mesh with each other.
[0018] Figure 2 shows a modified version of the gas exchange valve control system 10 of Figure 1, in which the intake cam 12 is non-rotatably mounted on the camshaft 11 and the exhaust cam 13 is rotatably mounted on the camshaft 11. Thus, a gear 17 that meshes with a gear 18 located on a separate drive shaft 14 is operably connected to the exhaust cam 13 in Figure 2, and the rotational motion of the separate drive shaft 14 is transmitted to the exhaust cam 13 via the gears 17 and 18 that mesh with each other.
[0019] Accordingly, in the exemplary embodiments of Figures 1 and 2, the cams rotatably mounted on each camshaft 11, the intake cam 12 in Figure 1 and the exhaust cam 13 in Figure 2, are individually operably connected to gears 15 and 17, respectively, rotatably mounted on the camshaft 11, and via the respective gears 15 and 17 rotatably positioned on each camshaft 11, engage with the respective gears 16 and 18 on each separate drive shaft 14, respectively, to drive the gears 15, 16 or 17, 18 that mesh with each other, and thus drive the respective cams, the intake cam 12 in Figure 1 and the exhaust cam 13 in Figure 2, starting from the drive shaft 14. The gears 16 and 18 are non-rotatably positioned on the drive shaft 14.
[0020] Figure 3 shows a further modification of the gas exchange valve control system 10 according to the present invention, in which two intake cams 15, each rotatably mounted on a camshaft 11, are assigned a common gear 15, similarly rotatably mounted on the camshaft 11, which meshes with a gear 16 non-rotatably mounted on a separate drive shaft 14. Thus, the number of gears 15 and 16 can be reduced, i.e., halved, compared to Figure 1.
[0021] The principle of Figure 3 can also be adapted to Figure 2 to drive two exhaust cams 13, each rotatably mounted via a common gear 17. The common gear 17 meshes with a gear 18 located on the drive shaft 14.
[0022] According to FIG. 4, the camshaft 11 is driven via a camshaft drive gear 19 provided on the camshaft 11, and a separate drive shaft 14 is driven via a drive shaft drive gear 20 provided on the same camshaft 11, and these are meshing with each other in FIG. 4. The camshaft drive gear 19 can be driven starting from the crankshaft in order to drive the camshaft 11. Starting from the camshaft 11, the separate drive shaft 14 can also be driven via the drive gears 19, 20 which are meshing with each other or engaging with each other.
[0023] According to FIG. 4, a phase adjuster 21 is assigned to the camshaft 11 and / or a phase adjuster 22 is assigned to the separate drive shaft 14. The camshaft 11 is twisted with respect to the camshaft drive gear 19 via the phase adjuster 21, and the drive shaft 14 is twisted with respect to the drive shaft drive gear 20 via the phase adjuster 22. Thereby, an independent flexible valve timing for the intake valve and the exhaust valve can be realized.
[0024] FIG. 5 shows a modification of FIG. 4, and in addition to the camshaft drive gear 19, there is a further camshaft drive gear 23 which finally serves to connect the camshaft 11 to the crankshaft. This can be advantageous for minimizing the installation space.
[0025] In the illustrated exemplary embodiment, the fuel cam 24 is further arranged non-rotatably and can be driven via each camshaft 11. The fuel cam 24 is used to control a fuel pump, particularly a high-pressure fuel pump for supplying fuel, and between each fuel pump and each cylinder, an electronically or electrically controllable fuel metering device, particularly a fuel injector, is connected, and via this fuel metering device, fuel can finally be supplied individually to each cylinder.
[0026] As already explained, in the gas exchange valve control system 10 according to the present invention, by not fixing one of the intake cam 12 and exhaust cam 13 provided on each camshaft 11 to the camshaft 11 but making it rotatable, the valve timing of the intake valve and exhaust valve can be freely adjusted. Each cam, which is rotatably mounted on each camshaft 11, can be driven by a separate drive shaft 14. The camshaft 11 and the separate drive shaft 14 are phase-adjustable via phase adjusters 21 and 22, respectively.
[0027] Furthermore, the present invention relates to an internal combustion engine equipped with a gas exchange valve control system 10 configured as described above. The same system is also useful for controlling at least gas exchange valves, i.e., intake and exhaust valves of cylinders of an internal combustion engine arranged in a row, and in particular for controlling a fuel pump. When the cylinders form a row of cylinders arranged adjacent to each other, the gas exchange valve control system 10 preferentially interacts with each row of cylinders.
[0028] The internal combustion engine according to the present invention is particularly a large internal combustion engine, such as one used in ships. In a large internal combustion engine, the cylinder has a piston diameter of at least 140 mm, and particularly at least 175 mm. [Explanation of Symbols]
[0029] 10. Gas exchange valve control system 11 Camshaft 12 Intake Cam 13 Exhaust Cam 14 Drive shaft 15 gears 16 gears 17 gears 18 gears 19 Camshaft drive gear 20 Drive shaft drive gear 21 Phase Adjuster 22 Phase Adjuster 23 Camshaft drive gear 24 Fuel Cam
Claims
1. A gas exchange valve control system (10) for an internal combustion engine, particularly a large internal combustion engine, The invention provides at least one camshaft (11) that supports an intake cam (12) for controlling intake valves and an exhaust cam (13) for controlling exhaust valves for a cylinder row arranged adjacent to each other, wherein in the first modification the intake cam (12) and in the second modification the exhaust cam (13) are non-rotatably mounted on each camshaft (11) and can be driven by each camshaft (11). In the first modification, the exhaust cam (13) is rotatably mounted on the respective camshaft (11), and in the second modification, the intake cam (12) is rotatably mounted on the respective camshaft (11), and can be driven by a separate driveshaft (14). Gas exchange valve control system.
2. The gas exchange valve control system according to claim 1, characterized in that each of the camshafts (11) and each of the separate drive shafts (14) extends parallel to each other.
3. The gas exchange valve control system according to claim 1 or 2, characterized in that each of the camshafts (11) and each of the separate drive shafts (14) are engaged via drive gears (19, 20), that is, via a camshaft drive gear (19) located on each of the camshafts (11) and a drive shaft drive gear (20) located on each of the drive shafts (14).
4. The gas exchange valve control system according to claim 3, characterized in that each of the camshafts (11) is assigned a phase adjuster (21) for twisting the respective camshaft (11) with respect to the camshaft drive gear (19).
5. The gas exchange valve control system according to claim 3 or 4, characterized in that each of the drive shafts (14) is assigned a phase adjuster (22) for twisting each of the drive shafts (14) relative to the drive shaft drive gear (20).
6. A gas exchange valve control system according to any one of claims 1 to 5, characterized in that each of the camshafts (11) is driveable from the crankshaft, and each of the drive shafts (14) is driveable from each of the camshafts (11).
7. A gas exchange valve control system according to any one of claims 1 to 6, characterized in that in the first modification, each exhaust cam (13) is engaged with the gears (16, 18) of the respective drive shaft (14) via individual gears (15, 17), and in the second modification, each intake cam (12) is engaged with the gears (16, 18) of the respective drive shaft (14).
8. The gas exchange valve control system according to any one of claims 1 to 6, characterized in that in the first modification, each of the two exhaust cams (13), and in the second modification, each of the two intake cams (12), are engaged with the gears (16, 18) of their respective drive shafts (14) via a common gear (15, 17).
9. A gas exchange valve control system according to any one of claims 1 to 8, characterized in that a fuel cam (24) used to control the fuel pump is non-rotatably positioned on each camshaft (11) and can be driven from each camshaft (11).
10. The gas exchange valve control system according to claim 9, characterized in that the fuel delivered by the fuel pump can be individually introduced into each cylinder via an electronically or electrically controllable fuel metering device.
11. Internal combustion engines, especially large internal combustion engines, The present invention comprises a plurality of cylinders, each cylinder having a gas exchange valve comprising at least one intake valve and at least one exhaust valve, for supplying combustion air to each cylinder individually via at least one intake valve and for discharging exhaust gas from each cylinder individually via at least one exhaust valve. The cylinders form at least one cylinder row of cylinders arranged adjacent to each other, and each cylinder in the cylinder row is assigned a gas exchange valve control system (10) according to any one of claims 1 to 10, which controls the intake valve and exhaust valve of the cylinder in the cylinder row. Internal combustion engine.